How to convert a string into a variable name and assign it a cell of data?
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I've read multiple post: converting a string into a variable name seems quite problematic, but in my case convenient.
It's about to load multiple pictures from a folder.
But in order to not get confused with all the images, I want to assign the image name right to its data.
Here's my code, that just serves for loading the images:
clear
%% Load Picture Infos
Folder = '/Users/niklaskurz/Downloads/Bilderauswahl/*.jpg';
PictureLinks = imageDatastore(Folder);
PictureNames = dir(Folder);
PictureEdits = cell(2,1);
i = 1;
while hasdata(PictureLinks)
PictureEdits{1,i} = PictureNames(i).name;
PictureEdits{2,i} = read(PictureLinks);
i = i + 1;
end
This creates a cell with PictureNames in the first row and the data in the second. However it would be incredible having the name of the picture to be assigned to its data straight away, so that it can be called.
5 Comments
Stephen23
on 7 Dec 2022
Edited: Stephen23
on 7 Dec 2022
"Maybe an improvement for Matlab would be setting a stable Function, that extracts the File name of an image and assigns it to its image data, since this is a practical way of remembering what is what."
I already showed you a very simple way of keeping the filenames and imported data together, using the structure array that you already have. The approach I showed you is simpler, neater, and much more efficient than what you are trying to do.
Given how TMW is actively moving away from (and discouraging) the complex, inefficient, anti-pattern paradigm that you prefer, such a function is very unlikely. Not only that, given that many characters are valid in filenames (varying by OS) but not in variable names, such a function would require a complex set of rules for modifying the names and avoiding namespace clashes. It would not be simpler, it would be much more complex than you think: usually when beginners make suggestions like this, they are thinking only about their specific scenario, and they forget that TMW actually writes MATLAB to work for all scenarios for all filenames for all locales for all OSs for all users. Indexing works in exactly the same way for all of those, your concept does not.
Accepted Answer
Florian Bidaud
on 6 Dec 2022
Edited: Florian Bidaud
on 6 Dec 2022
You can use the function eval, although it is not recommanded.
For example doing something like:
eval([strVarName '=' strVarValue ';'])
3 Comments
Walter Roberson
on 6 Dec 2022
eval([extractBefore(PictureNames(1).name, '.jpg'), '= PictureEdits{2,1}']);
Walter Roberson
on 7 Dec 2022
This code will fail the first time it encounters a .JPG file. Which is likely, since on MS Windows by default, *.jpg also selects .JPG files.
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